Combining voice and video communication is a desirable service now just being offered over land telecommunication lines. The video portion of the communication requires a considerably wider bandwidth than the voice communication. Accordingly the video portion of the signal may be transmitted over the voice transmission channel which conventionally has a relatively narrow bandwidth compared with the bandwidth requirements of the video signal. This results in significant degradation of the video portion of the communication.
With the increasing scope of wireless communication services offend, combined video services are a very desirable enhancement to be offered the wireless subscriber. A limitation in offering such service is the disparate bandwidth requirements of the voice and video communication signal. This may be remedied in a wireless system by the use of separate voice and video communication channels. The use of separate channels is undesirable for many reasons including multi-pathing differences of the separate wireless transmissions and the accompanying difficulties of synchronizing the two channels as well as the overall bandwidth requirements.
Expansion of the bandwidth of a vocal channel to accommodate real time image transmissions over a voice channel in both land-line and wireless systems is not economically feasible both in terms of capital expense and operating expense.